1. Field of the Invention
The present invention relates to automatic photoprocessing equipment for the processing of undeveloped photographic film. In particular, the invention relates to a spindle rotation failure sensor for a horizontal in-line film disc processor.
2. Description of the Prior Art
The processing of photographic film includes contacting the film with a plurality of processing fluids in a selected order and for selected time periods to properly develop the images thereon. Because the film is light-sensitive, the processing must be done in the dark. Once the film has been contacted with the fluids as desired, it is also necessary to dry the film before further processing can be performed, such as making prints or slides. Numerous machines have been devised for processing film in strip or web form. However, this type of apparatus is wholly unsuited for processing film in a disc film format where the individual photographic images are located circumferentially about a central hub, as shown, for example, in U.S. Pat. No. 4,194,822, granted to Sethi on Mar. 25, 1980. Thus, the introduction of cameras using film in a disc film format has led to the development of processing machines specifically for film discs.
Processing machines and devices developed specifically for disc film include those shown in the following U.S. patents:
______________________________________ Patentee U.S. Pat. No. Issue Date ______________________________________ Michal 4,252,430 02/24/81 Harvey 4,188,106 02/12/80 Solomon 4,178,091 12/11/79 Hutchinson 4,167,320 09/11/79 Harvey 4,112,454 09/05/78 Hutchinson 4,112,453 09/05/78 Patton 4,112,452 09/05/78 ______________________________________
In addition to the devices shown in these patents, several disc film processing devices are shown in the following Research Disclosures:
______________________________________ 172 Research Disclosure, August 1978 Disclosure No. Title ______________________________________ 17258 Horizontal In-Line Photofinishing Processor 17262 Method and Apparatus for Treating Elements of Photographic Film 17263 Improved Horizontal Film-Processing Apparatus 17264 Improved Vertical Film-Processing Apparatus 17265 Rotary Film-Processing Apparatus ______________________________________
______________________________________ 174 Research Disclosure, October 1978 Disclosure No. Title ______________________________________ 17429 Processor Concept ______________________________________
Disc film processing machines are also shown in two brochures of the Eastman Kodak Company of Rochester, N.Y, entitled "KODAK Disc Film Processor, Model 200" and "KODAK Disc Film Processor, Model 1000."
Since the processing of photographic film must be carried out in the dark, a film disc processing machine must either be located in a darkroom or have some means for shielding the undeveloped film discs from light during processing to prevent damage to the photographic images on the film. As shown in many of the devices disclosed above, it is efficient to process a plurality of the film discs together by mounting them on a spindle, which is then carried through the processor from start to finish as a unit. The spindle unit is conveyed from tank to tank of processing fluid in sequence, with the spindle being rotated to uniformly coat the film discs thereon with processing fluid.
None of these prior art devices disclose an automatic processor for undeveloped photographic film discs which has a sensor to indicate when the spindle (carrying the film discs) at a certain processing station is not being properly rotated by the processor. Due to the fact that such processing operations must be carried out in the dark, an operator cannot easily view the processing operation to monitor its effectiveness. Therefore it becomes important to have a means to immediately indicate to the operator when a malfunction occurs during processing, such as when a spindle is not properly rotated at a processing station. In the case of a fluid processing station, the failure of the spindle to be rotated can seriously damage or destroy the photographic images carried on the film discs on that spindle, since (in the case of partial immersion of the film discs in processing fluid) some of the images on the film discs would be over-contacted with processing fluid while others would not be contacted at all. In order to process each and every film disc properly, the processing operation should take place without any interruption or interference, and if such problems occur, they must be rectified immediately.